Shielding device

ABSTRACT

A shielding device configured to provide EMI or ESD protection to an electronic component ( 80 ) comprises a cover ( 83 ), and a wall ( 10 ) of a resilient material. By molding the resilient material under the influence of a magnetic field provided by a number of separate magnets, a dispersed plurality of magnetically attractable particles in the material are concentrated in strings ( 11 ) extending between a lower ( 12 ) and upper ( 13 ) end of the wall. The cover is attached to connect to the strings affixed in the solidified wall at the upper end of the wall, and at the lower end of the wall the strings are placed in contact with a ground trace ( 82 ) formed around the component to be shielded, thereby forming a Faraday cage about the component.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.11/401,630, filed Apr. 11, 2006, and claims the benefit of and priorityto U.S. Provisional Patent Application No. 60/777,971, filed Mar. 1,2006; entitled Shielding Device, the disclosure of which is herebyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of shielding devices forelectric and electronic components. Typically, such shielding devicesare either used to protect components from electromagnetic radiation orinterference (EMI) or electrostatic discharge (ESD), or to protect othercomponents from electromagnetic radiation emitted from the shieldedcomponent. More specifically, the invention relates to a shieldingdevice, a method for producing such a shielding device, and a method forshielding a component, wherein a wall of the shielding device is madefrom a resilient material in which strings of electrically conductiveparticles are concentrated in strings, extending between an upper wallend and a lower wall end.

BACKGROUND

The mobile phone industry has had an enormous development both regardingquality of service and transmission capabilities, as well as thetechnology for producing advanced communications terminals. In only acouple of decades the communication systems have gone from analogue todigital, and at the same time the dimensions of the communicationterminals have gone from briefcase size to the pocket size phones oftoday. Still today, mobile phones are getting smaller and smaller andthe size is generally considered to be an important factor for the endcustomer. The development in electronics has made it possible tominiaturize the components of the terminals, at the same time making theterminals capable of performing more advanced functions and services.

Mobile phones communicate by radio, and electromagnetic interference(EMI) will therefore always be an issue to handle. Electromagneticfields generated from the radio part of the phone may cause interferenceproblems ion the processor part, and vice versa. In order to shieldsensitive equipment from electromagnetic radiation, or to protect themfrom electrostatic discharge, such equipment is often provided with ashielding device in the form of a metal casing or can, enclosing theequipment towards a carrier, typically a printed circuit board (PCB). Ingeneral, the can is soldered to the PCB to provide a conductive seam toa support surface on the PCB. An advantage with shield cans is that thecost of the can as such is low. However, a problem related to thismethod is that if a component below the soldered shield can is to bereplaced or removed, the can first needs to be removed by heating andthen be re-soldered after finishing the job with the component. This isa time-consuming and costly process.

An alternative solution is to apply a conductive gasket over aconductive trace on a PCB about the equipment to be shielded, and thenapply a cover on top of the gasket. Such a conductive gasket may beprovided as a string of silicone, in which silver grains arehomogenously dispersed. A problem related to this technique is that suchconductive gaskets generally are relatively hard. Moreover, they tend tobecome even harder by ageing. This means that the force needed to obtainsufficient contact between the cover and the conductive trace is quitehigh. Furthermore, in order to obtain a reasonable softness in thesilicone, it cannot comprise a large amount of metal grains, which assuch are non-compressible. As a result the contact resistance betweenthe conductive silicone and an engaging surface is relatively low.Furthermore, the material cost for silver-containing silicone isrelatively high.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a shielding device,and a method for producing a shielding device, which is flexible interms of assembly and disassembly. The invention therefore provides ashielding device and a method for producing the shield device where theshielding device is non-soldered, but still cost effective.

According to a first aspect of the invention, the stated object isfulfilled by means of a shielding device for an electronic component,comprising

a wall of a resilient material, having a lower end and an upper end;

a plurality of particles of a magnetically attractable material,concentrated in strings extending within the wall from the lower end tothe upper end;

a cover having an electrically conductive layer, connected to thestrings at the upper end of the wall.

In one embodiment of the shielding device, the wall encompasses an area,and the cover is engaged to the upper end of the wall around that area.

In one embodiment of the shielding device, the cover is a sheet ofmetal.

In one embodiment of the shielding device, the electrically conductivelayer is made of a non-magnetic metal.

In one embodiment of the shielding device, the cover is adhered to theupper end of the wall by means of a conductive adhesive.

In one embodiment of the shielding device, the cover is pressed intoengagement with the upper end of the wall by means of an attachmentmember.

In one embodiment of the shielding device, the plurality of particlesare coated with a conduction-enhancing metal layer.

In one embodiment of the shielding device, the plurality of particlesare coated with a layer of gold.

In one embodiment of the shielding device, the plurality of particlesare coated with a layer of silver.

In one embodiment of the shielding device, the lower and of the wall hasa stepper profile defined by a shoulder, configured to engage a steppedcarrier surface.

In one embodiment of the shielding device, the wall encompasses an area,and an interior partition wall member divides the area into two separatesub areas.

According to a second aspect of the invention, the stated object isfulfilled by means of a method for manufacturing a shielding deviceincluding a wall and a cover connected to an upper wall end, comprisingthe steps of:

injecting a moldable material, including a dispersed plurality ofparticles of a magnetically attractable material, into a mold tool;

providing a magnetic field over the mold tool, such that the particlesare concentrated in strings extending within a cavity of the mold tool;

solidifying the molding material to form a resilient wall element, inwhich the strings are affixed extending from a lower wall end to theupper wall end.

In one embodiment, the method comprises the steps of:

releasing the molded wall from the mold tool;

applying the cover to the solidified wall.

In one embodiment, the method comprises the steps of:

releasing the molded wall from the mold tool;

applying the cover to the solidified wall by means of a conductiveadhesive.

In one embodiment, the method comprises the steps of:

releasing the molded wall from the mold tool;

applying the cover to the solidified wall by pressing, such that aconductive layer of the cover is connected to the strings at the upperwall end.

In one embodiment, the method comprises the steps of:

placing the cover in the mold tool;

attaching the wall to the cover in the step of solidifying the moldingmaterial;

releasing the molded wall with the attached cover from the mold tool.

According to a third aspect of the invention, the stated object isfulfilled by means of a method for shielding a component, comprising thesteps of:

providing a wall of a resilient moldable material, having a lower endand an upper end, in which wall a plurality of particles of amagnetically attractable material are concentrated in strings extendingfrom the lower end to the upper end;

providing a cover having an electrically conductive layer, connected tothe strings at the upper end of the wall;

placing the wall on a carrier surface on which a component is attached,such that a ground portion on the carrier surface is connected to thestrings at the lower end of the wall.

In one embodiment, the wall and the ground portion encompasses an areain which the component is positioned.

In one embodiment, the method comprises the step of:

attaching the cover to the wall by means of a releasable attachmentmember configured to press the cover against the upper wall end.

In one embodiment, the method comprises the step of:

attaching the cover to the wall by means of a conductive adhesive.

In one embodiment, the method comprises the step of:

attaching the wall to the carrier surface by means of a releasableattachment member configured to press wall against the ground portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will becomemore apparent from the following description of preferred embodiments,with reference to the accompanying drawings, on which

FIGS. 1 and 2 schematically illustrate a wall forming part of ashielding device according to an embodiment of the invention;

FIG. 3 schematically illustrates a view from above of a mold tool memberfor manufacturing a wall according to an embodiment of the invention;

FIG. 4 illustrates the assembly of a mold tool for use in an embodimentof the invention;

FIGS. 5 and 6 illustrate cross-sectional views of different embodimentsof assembled mold tools for use in accordance with the invention;

FIG. 7 illustrates a molding system usable for manufacturing a shieldingdevice in accordance with an embodiment of the invention;

FIG. 8 schematically illustrates an assembly of a shielding device overa component in accordance with an embodiment of the invention; and

FIG. 9 schematically illustrates an assembly of a shielding device overtwo components and partly covering two sandwiched PCBs in accordancewith an embodiment of the invention; and

FIG. 10 schematically illustrate a wall forming part of a shieldingdevice according to a variant of the embodiment of FIG. 1, with aninterior partition wall separately shielding off two compartments orareas.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present description refers to shielding devices for electroniccomponents, for the purpose of EMI or ESD protection. The invention willin certain aspects be referred to as implemented in a mobile phone, as ashielding device over a circuit attached to a printed circuit board(PCB) of the phone. This should merely be regarded as an example usablefor understanding the invention, and not as a limitation to that fieldof use. More specifically, in any context where there is a need toshield a component or circuit to minimize EMI or to protect thecomponent from ESD, the present invention may be used in a suitableembodiment. Furthermore, it should be emphasized that the term“comprising” or “comprises” when used in this description and in theappended claims to indicate included features, elements or steps, is inno way to be interpreted as excluding the presence of other features,elements or steps than those expressed or stated.

A shielding device according to the invention comprises a wall and acover, which together form a shielding cavity to be attached to a groundsurface to close the cavity, preferably around an electronic component.An embodiment of a shielding device according to the invention will bedescribed, as well as a tool and a method for manufacturing theshielding device, and a method for shielding a component.

FIG. 1 schematically illustrates a wall 10 for a shielding deviceaccording to an embodiment of the invention from an elevated view, andFIG. 2 illustrates the same wall 10 in phantom to clearly shown theinternal structure of wall 10. In the illustrated embodiment, wall 10encloses a rectangular area, but it should be noted that the wall may infact take any shape, and can therefore freely be designed dependent onspecific requirements such as the shape of the component or componentsto be encapsulated. Wall 10 is predominantly formed of a moldableresilient material, preferably a silicone material. Inside wall 10, anumber of strings 11 of en electrically conductive material are formed.These strings extend from a lower end 12 of wall 10 to an upper end 13of wall 10. In the shown embodiment, strings 11 extend substantiallystraight, and perpendicular to the extension of the wall. It should benoted, though, that strings 11 as well as the cross-section of wall 10may also be curved. Strings 11 are formed of a concentrated amount ofgrains or particles comprising a magnetically attractable metal, such asiron, nickel or ferrite. This way, the formation of strings 11 is madepossible by means of a magnetic tool as will be described. In order toenhance the conductivity of the strings, the grains or particles may becoated with a layer of e.g. gold, silver or copper.

FIGS. 3-7 schematically illustrate a mold tool for manufacturing wall10. In FIG. 3 a mold base 30 is seen from above. Mold base 30 isprovided in a non-magnetic material, such as aluminum or stainlesssteel, and is provided with a groove 31 which defines the shape of thewall to mold. At selected positions in groove 31, magnets 32 arearranged, preferably flush with the bottom of groove 31. One or moreconduits 33 are further provided in mold base 30, extending from anoutside wall of mold base 30 to groove 31. In the examples shown,conduits 33 extend through mold base 30. As an alternative, a channelmay be formed in the surface of mold base 30 between the outside wall ofmold base 30 and groove 31, which channel is closed when an opposingmold cover is attached to mold base 30.

FIG. 4 illustrates an elevated view of the mold tool, including moldbase 30 and a mold cover 40. Mold cover 40 may also comprise a groove 41in a similar manner as mold base 30 has groove 31. Alternatively, moldcover 40 may have a flat surface devised to engage mold base 30.Furthermore, mold cover 40 is provided with magnets 42, disposedopposite magnets 32. Guide pins (not shown) or the like are preferablyprovided to correctly mate mold base 30 and mold cover 40, such thatmagnets 32 and 42 are properly aligned with each other.

FIGS. 5 and 6 illustrate two embodiments of the mold tool, in which moldbase 30 has been engaged with mold cover 40, in a cross-sectional viewthrough A-A of FIG. 3. These drawings clearly shown how magnets 32 and42 are aligned with respect to each other. Magnets 32 and 42 may bestrong permanent magnets, and are in such a case arranged such thatmagnets 32 are arranged with the north magnetic pole towards theinterior of the mold tool, whereas magnets 42 are arranged with thesouth magnetic pole towards the interior of the mold, or vice versa. Inan alternative embodiment, magnets 32 and 42 form end poles of anelectromagnet, and are connected by a magnetic yoke 50. Yoke 50 is onlyschematically illustrated in phantom, and would typically also beprovided with windings connected to an electric power supply accordingto the established art. For the sake of simplicity, yoke 50 is onlyillustrated in FIG. 5, but may just as well be included in theembodiment of FIG. 6. An advantage with an electromagnet is that themagnetic field may be turned off, thereby simplifying release of themolded wall.

In the embodiment of FIG. 5, mold cover 40 is provided with a recess 41,similar or identical to recess 31 in mold base 30. An advantage withsuch an embodiment is that after completed molding and separation ofbase 30 and cover 40, the molded wall will project from mold base 30, ormold cover 40, which makes it easier to release the molded wall from themold tool.

In the embodiment of FIG. 6, mold cover 40 is substantially flat at itsengagement surface towards mold base 30. Such an embodiment isadvantageous if the wall to be molded is to be adhered to a shieldingcover. When manufacturing a shielding device where wall and cover arejoined, a cover of an electrically but non-magnetic material is placedbetween the mold parts 30 and 40, respectively, before introduction ofthe molding material. Portions of the shielding cover facing recess 31may also be provided with an adhering promoter, as is well known in theart of silicone molding.

FIG. 7 schematically illustrates a molding system according to anembodiment of the invention, comprising a mold tool 70 includingopposing mold parts 30 and 40, respectively according to any of thedescribed embodiments, with a plurality of opposing magnets 32 and 42,respectively. A molding material source 71 comprises a molding materialcontainer 72 and preferably a first heater device 73. The moldingmaterial preferably includes a silicone material, in which a pluralityof grains or particles of a magnetically attractable material aredispersed. The amount of particles included is selected dependent on thedesired resiliency, and to the structure to form, more specifically thewidth of strings 11 compared to the pitch between strings 11 and thewidth of wall 10. As an example, assume that the shielding compartmentto be obtained has a height of 2 mm, and covers an area of 1×1 cm. Thewall may then be designed to have a thickness of t=1 mm, as defined bythe width of groove 31 in the mold tool. The strings 11 to be formed byattraction from magnets 32 and 42, may not be absolutely even, but anaverage string diameter of d=0.5 mm can be assessed. The pitch betweenthe strings has to be larger than the width of strings 11, and as anexample we can assess a pitch of p=1 mm. The volume V_(s) of the stringscould be roughly calculated as

V _(s) =h*πd ²/4,

where h is the height of the wall, and the total wall volume could beroughly calculated as

V _(w) =h*p*t.

The relative volume amount of metal particles in the molding material,for the given example, would then be about

V _(s) /V _(w)=19.6%.

A possible range for the volume ration is believed to be 5-30%. In anycase, a molded element of such a material would be fairly hard if themetal particles were evenly dispersed in the silicone of the finalproduct. However, when the metal particles are concentrated in strings11 by means of magnetic attraction in the mold tool, the resultingmolded element obtains characteristics similar to a studded winter tire.The bulk of the wall will remain soft and resilient, whereas the endportions of the strings will engage the conductive surfaces pressed tothe wall ends, whereby good low-resistive electrical contact is obtainedwithout requiring a high compression force.

First heater device 73 is preferably configured to hold a temperaturesufficient to make the molding material fluid. Typically, the moldingmaterial includes an agent devised to assist cross-linking of themolecules in the molding material when raised above a certaintemperature T_(m), e.g. 120° C. The molding material in container 72 ispreferably controlled by first heater device 73 to hold a raisedtemperature which is still lower than T_(m). A second heater device 74may be arranged between container 72 and mold tool 70, configured toraise the temperature another notch immediately before injection of themolding material into mold tool 70. As an example, container 72 may hold100° C., whereas second heater device 74 is configured to raise thetemperature to 120° C. The mold tool 70 as such preferably holds atemperature of 150-180° C., by means of a third heater device (notshown) connected to the mold parts 30 and/or 40. From the moldingmaterial source 71, possibly via second heater device 74, the moldingmaterial is injected into mold 70 through one or more conduits 33.Silicone typically cross-links very fast, in the range of a minute orso, and the magnetic field between opposing magnets 32 and 42 istherefore preferably present from the start, i.e. before injection. Forpermanent magnets, this would typically be the case. However, analternative embodiment may include displaceable permanent magnets 32 and42, which are displaced towards each other to the position shown inFIGS. 5 and 6, after injection of the molding material. For anelectromagnet solution, the magnetic field may selectively by turned onbefore or after injection of the molding material.

When the molding material is injected and the magnetic field is presentbetween opposing magnets 32 and 42, the magnetically attractableparticles dispersed in the molding material will tend to concentrate tostrings 11, drawn black in FIG. 7, extending between the opposingmagnets. The strings are illustrated in the drawings as cylindricalpillars, but may of course be less even, since the shape ispredominantly determined by the shape of the magnetic field.

Once the molding material is solidified, typically by cross-linking, toform the wall 10 with built-in strings 11, the mold tool 70 is openedfor removal of the molded wall 10, with or without attached shieldingcover.

FIG. 8 illustrates a simple embodiment of application of a shieldingdevice according to an embodiment of the invention. A component 80 isattached to a surface of a carrier 81, such as a PCB. A grounded portion82 forms a ground trace surrounding component 80. In order to shield offEMI or protect the component from ESD, a wall 10 is placed on top of theground trace to encompass component 80. Wall 10 has a lower end having ashape corresponding to ground trace 82, such that the lower ends ofstrings 11 engage ground trace 82. A shielding cover 83 is placed incontact with the upper end of wall 10, such that upper ends of strings11 are placed in contact with a conductive portion on cover 83. Cover 83may e.g. be a sheet of metal, or a plastic cover which is metallized bycoating. Furthermore, cover 83 may be firmly attached to wall 10 bymolding, as described above, by using a conductive adhesive, which iscommercially available from e.g. 3M, or simply by pressing the coverinto contact with the upper end of wall 10. The cover may be made of amagnetic or a non-magnetic material, but if the wall is molded to thecover it is preferably made of a non-magnetic material. In any case, anattachment member (not shown) is preferably provided to press cover 83towards carrier 81, to ensure good electrical contact through strings11. The attachment member may e.g. be a biased spring mechanism providedby a clamp, or indirectly by means of another element such as a batterybeing pressed against cover 83. Another alternative is to attach thecover 83 to carrier 81 by screws passing through holes in the cover,preferably formed in ears extending outside the perimeter of wall 10.

The invention as described above has many benefits. A wall for ashielding device is obtained which is conductive but softer thanconductive gaskets with an even distribution of conductive particles. Byarranging the conductive particles in strings a fence-like structure isobtained within the wall, which will act as a Faraday cage when attachedbetween a ground plane and a cover. The solution is also advantageouscompared to soldered solutions, in that the shielding device is easilydisassembled when needed. Furthermore, since the wall is molded, itsshape can be freely designed with respect to the intended use. In fact,the carrier surface to which the wall is to be attached need not even beflat.

FIG. 9 schematically illustrates an embodiment of the invention similarto the embodiment of FIG. 8, where a component 80 is attached to asurface of carrier 81, such as a first PCB. Furthermore, a second PCB 91is attached to the carrier surface of first PCB 81, e.g. by soldering,gluing, screwing or any other suitable way. Second PCB 91 supports asecond component 90 on its outer surface. Typically, second PCB 91includes more components, only second component 90 being shown for thesake of simplicity. As an example, the first PCB 81 is a main PCB for aradio communication terminal such as a mobile phone. Second PCB 91 maybe an additional PCB which is separately attached to first PCB 81 inorder to adapt the terminal to specific operating conditions of themarket in which it is to operate. For instance, component 90 may be aradio component, specifically adapted for use in a certain communicationsystem. By using a main PCB 81 on which all or most of the attachedcomponents can be used in a plurality of communication systems withdifferent frequency bands, an adapting the terminal to specificconditions of a certain network by attaching a particular additional PCB91 to main PCB 81, cost and assembly time can be saved. A groundedportion 82 forms a ground trace partly or completely surroundingcomponent 80. Furthermore, a second ground trace 92 is preferably formedon second PCB 91, which together with first ground trace 82 encompassesboth component 80 and component 90. The edge portions of second groundtrace 92 may be galvanically connected to first ground trace 82 bysoldering at the edge of the second PCB 91, or e.g. by pressing aconnection pad (not shown), which is connected to second ground trace 92but disposed on the backside of second PCB 91, to first ground trace 82.As an alternative, first ground trace 82 is shaped to encompasscomponent 80 on the surface of first PCB 81, whereas second ground trace92 is shaped to encompass component 90 on the surface of second PCB 91.In order to shield off EMI or protect components 80 and 90 from ESD, awall 93 is placed on top of the ground traces to encompass components.Wall 93 has a lower end 94 having a shape corresponding to the groundtrace 82 and 92, such that the lower ends of strings 11 engage theground traces. Furthermore, lower end 94 is shaped to climb from thesurface of PCB 81 over the edge and onto the surface of second PCB 91.This is achieved by forming wall 93 with shoulder portions 95dimensioned to the height, or thickness, of second PCB 91. A shieldingcover 96 is placed in contact with the upper end of wall 93, such thatupper ends of strings 11 are placed in contact with a conductive portionon cover 96. As for the embodiment of FIG. 8, cover 96 may e.g. be asheet of metal, or a plastic cover which is metallized by coating.Furthermore, cover 96 may be firmly attached to wall 93 in any of theways described with reference to FIG. 8. Furthermore, the molded wallneed not encompass an area as shown in the drawings. Instead, wall 10may be provided e.g. as a U-shaped wall section to be assembled to aground trace and also to an upright supplementary wall member formingpart of another object, such as another shielding device, wherein thewall section and the supplementary wall together for a closed wall.

In one embodiment as illustrated in FIG. 10, the wall structure 100includes an internal partition wall 101, also provided with affixedstrings 11 as previously described. Such a wall structure can be shapedto encompass a plurality of components separately or in groups, afterwhich a single cover can be placed over the entire wall structure toclose separate shielding compartments. As was explained with referenceto FIG. 9, one version of such an embodiment may be to provide twoseparate and closed ground traces 82 and 92, respectively, about therespective components 80 and 90. A wall structure 101 as shown in FIG.10, further provided with shoulder portions as shown in FIG. 9, maysuitable used for such an embodiment.

An example of dimensions for the shielding device have been outlinedabove. The invention is as such particularly advantageous for compactshields, but it should be noted that the design is in no way restrictedto use within any specific dimension ranges. Besides offering goodelectrical connection to the cover and to the ground portion around thecomponent to be shielded for the purpose of EMI or ESD protection, theresiliency of the molded silicone material offers protection againstmoisture and dust.

The foregoing has described the principles, preferred embodiments andmodes of operation of the present invention. However, the abovedescribed embodiments should be regarded as illustrative rather thanrestrictive, and it should be appreciated that variations may be made inthose embodiments by those skilled in the arts without departing fromthe scope of the present invention as defined in the appended claims.

1. A method for manufacturing a shielding device including a wall and acover connected to an upper end of the wall, the method comprising:injecting a moldable material, including a dispersed plurality ofparticles of a magnetically attractable material, into a cavity of amold tool; forming a magnetic field through the mold tool to cause theparticles to be concentrated into strings extending through the moldablematerial within the cavity of the mold tool; and solidifying themoldable material to form a resilient molded wall in which the particlestrings are fixated extending from a lower wall to the upper end of themolded wall.
 2. The method of claim 1, further comprising: releasing themolded wall from the mold tool; and connecting the cover to the moldedwall.
 3. The method of claim 1, further comprising: releasing the moldedwall from the mold tool; and connecting the cover to the molded wallusing a conductive adhesive.
 4. The method of claim 1, furthercomprising: releasing the molded wall from the mold tool; and connectingthe cover to the molded wall by pressing the cover and the molded walltogether and so that a conductive layer of the cover is connected to theparticle strings at the upper end of the molded wall.
 5. The method ofclaim 1, further comprising: placing the cover in the mold tool;connecting the moldable material to the cover during solidification ofthe molding material when forming the molded wall; and releasing themolded wall with the connected cover from the mold tool.
 6. The methodof claim 1, further comprising: connecting the lower end of the moldedwall to a ground portion of a carrier surface; and connecting the coverto the molded wall so that a conductive layer of the cover is connectedto the particle strings at the upper end of the molded wall.
 7. Themethod of claim 6, wherein the connection of the cover to the moldedwall is carried out before connection of the lower end of the moldedwall to the ground portion of the carrier surface.
 8. The method ofclaim 6, wherein connecting the lower end of the molded wall to a groundportion of a carrier surface comprises: enclosing side surfaces and atop surface of a component attached to the carrier surface with themolded wall and the cover.
 9. A method for shielding a component, themethod comprising: providing a wall of a resilient moldable material,the wall having a lower end and an upper end, and the wall encloses aplurality of particles of a magnetically attractable material that areconcentrated in strings extending from the lower end to the upper end ofthe wall; providing a cover having an electrically conductive layer, thecover connected to the particle strings at the upper end of the wall;placing the wall on a carrier surface on which a component is attached,and so that a ground portion on the carrier surface is connected to theparticle strings at the lower end of the wall.
 10. The method of claim9, wherein the wall, the ground portion of the carrier surface, and thecover enclose the component.
 11. The method of claim 9, furthercomprising: connecting the cover to the wall using a releasableattachment member that is configured to press the cover against theupper end of the wall.
 12. The method of claim 9, further comprising:connecting the cover to the wall using a conductive adhesive.
 13. Themethod of claim 9, further comprising: connecting the wall to thecarrier surface using a releasable attachment member that is configuredto press the wall against the ground portion of the carrier surface.